<?php
// Disallow direct access to this file
defined('_JEXEC') or die('Restricted access');

/*
 * This is a PHP library that handles calling reCAPTCHA.
 *    - Documentation and latest version
 *          http://recaptcha.net/plugins/php/
 *    - Get a reCAPTCHA API Key
 *          http://recaptcha.net/api/getkey
 *    - Discussion group
 *          http://groups.google.com/group/recaptcha
 *
 * Copyright (c) 2007 reCAPTCHA -- http://recaptcha.net
 * AUTHORS:
 *   Mike Crawford
 *   Ben Maurer
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

/**
 * The reCAPTCHA server URL's
 */
if(!defined('RECAPTCHA_API_SERVER') )
	define("RECAPTCHA_API_SERVER", "http://www.google.com/recaptcha/api/js/recaptcha_ajax.js");

if(!defined('RECAPTCHA_API_SECURE_SERVER') )
	define("RECAPTCHA_API_SECURE_SERVER", "https://www.google.com/recaptcha/api/js/recaptcha_ajax.js");

if(!defined('RECAPTCHA_VERIFY_SERVER') )
	define("RECAPTCHA_VERIFY_SERVER", "api-verify.recaptcha.net");

if(!function_exists('getRecaptchaHTMLData'))
{
	function getRecaptchaHTMLData()
	{
		$config		= CFactory::getConfig();
		$html		= '';
		
		$private	= $config->get('recaptchaprivate');
		$public		= $config->get('recaptchapublic');
		
		if($config->get('recaptcha') == 1 && !empty($private) && !empty($public))
		{
			$theme	= $config->get('recaptchatheme');
			$lang	= $config->get('recaptchalang');
			$html	= recaptcha_get_html_data( $public , $theme , $lang , null , $config->get('recaptcha_secure') );
		}
		return $html;
	}
}


if(!function_exists('_recaptcha_qsencode'))
{
	/**
	 * Encodes the given data into a query string format
	 * @param $data - array of string elements to be encoded
	 * @return string - encoded request
	 */
	function _recaptcha_qsencode ($data) {
	        $req = "";
	        foreach ( $data as $key => $value )
	                $req .= $key . '=' . urlencode( stripslashes($value) ) . '&';
	
	        // Cut the last '&'
	        $req=substr($req,0,strlen($req)-1);
	        return $req;
	}
}


if(!function_exists('_recaptcha_http_post'))
{
	/**
	 * Submits an HTTP POST to a reCAPTCHA server
	 * @param string $host
	 * @param string $path
	 * @param array $data
	 * @param int port
	 * @return array response
	 */
	function _recaptcha_http_post($host, $path, $data, $port = 80) {
	
	        $req = _recaptcha_qsencode ($data);
	
	        $http_request  = "POST $path HTTP/1.0\r\n";
	        $http_request .= "Host: $host\r\n";
	        $http_request .= "Content-Type: application/x-www-form-urlencoded;\r\n";
	        $http_request .= "Content-Length: " . strlen($req) . "\r\n";
	        $http_request .= "User-Agent: reCAPTCHA/PHP\r\n";
	        $http_request .= "\r\n";
	        $http_request .= $req;
	
	        $response = '';
	        if( false == ( $fs = @fsockopen($host, $port, $errno, $errstr, 10) ) ) {
	                die ('Could not open socket');
	        }
	
	        fwrite($fs, $http_request);
	
	        while ( !feof($fs) )
	                $response .= fgets($fs, 1160); // One TCP-IP packet
	        fclose($fs);
	        $response = explode("\r\n\r\n", $response, 2);
	
	        return $response;
	}
}

if(!function_exists('recaptcha_get_html_data'))
{
	/**
	 * Gets the challenge HTML (javascript and non-javascript version).
	 * This is called from the browser, and the resulting reCAPTCHA HTML widget
	 * is embedded within the HTML form it was called from.
	 * @param string $pubkey A public key for reCAPTCHA
	 * @param string $error The error given by reCAPTCHA (optional, default is null)
	 * @param boolean $use_ssl Should the request be made over ssl? (optional, default is false)
	
	 * @return string - The HTML to be embedded in the user's form.
	 */
	function recaptcha_get_html_data($pubkey, $theme = 'red' , $lang = 'en' , $error = null, $use_ssl = false)
	{
		if ($pubkey == null || $pubkey == '') {
			die ("To use reCAPTCHA you must get an API key from <a href='http://recaptcha.net/api/getkey'>http://recaptcha.net/api/getkey</a>");
		}
		
		if ($use_ssl)
		{
	                $server = RECAPTCHA_API_SECURE_SERVER;
		} else {
	                $server = RECAPTCHA_API_SERVER;
	        }
	
	        $errorpart = "";
	        if ($error) {
	           $errorpart = "&amp;error=" . $error;
	        }

		// Use AJAX method to prevent operation aborted problems with IE
		return '<script type="text/javascript" src="' . $server . '"></script>
			<script type="text/javascript">
			joms.jQuery(document).ready(function(){
				Recaptcha.create("' . $pubkey . '", "recaptcha-image", { 
					theme: "' . $theme . '",
					lang: "' . $lang . '",
					tabindex: 0, 
					callback: Recaptcha.focus_response_field
				});
			});
			</script>
			<div id="recaptcha-image"></div>
		';
	}
}


if( !class_exists('ReCaptchaResponse') )
{
	/**
	 * A ReCaptchaResponse is returned from recaptcha_check_answer()
	 */
	class ReCaptchaResponse {
	        var $is_valid;
	        var $error;
	}
}


if(!function_exists('recaptcha_check_answer'))
{
	/**
	  * Calls an HTTP POST function to verify if the user's guess was correct
	  * @param string $privkey
	  * @param string $remoteip
	  * @param string $challenge
	  * @param string $response
	  * @param array $extra_params an array of extra variables to post to the server
	  * @return ReCaptchaResponse
	  */
	function recaptcha_check_answer ($privkey, $remoteip, $challenge, $response, $extra_params = array())
	{
		if ($privkey == null || $privkey == '') {
			die ("To use reCAPTCHA you must get an API key from <a href='http://recaptcha.net/api/getkey'>http://recaptcha.net/api/getkey</a>");
		}
	
		if ($remoteip == null || $remoteip == '') {
			die ("For security reasons, you must pass the remote ip to reCAPTCHA");
		}
	
		
		
	        //discard spam submissions
	        if ($challenge == null || strlen($challenge) == 0 || $response == null || strlen($response) == 0) {
	                $recaptcha_response = new ReCaptchaResponse();
	                $recaptcha_response->is_valid = false;
	                $recaptcha_response->error = 'incorrect-captcha-sol';
	                return $recaptcha_response;
	        }
	
	        $response = _recaptcha_http_post (RECAPTCHA_VERIFY_SERVER, "/verify",
	                                          array (
	                                                 'privatekey' => $privkey,
	                                                 'remoteip' => $remoteip,
	                                                 'challenge' => $challenge,
	                                                 'response' => $response
	                                                 ) + $extra_params
	                                          );
	
	        $answers = explode ("\n", $response [1]);
	        $recaptcha_response = new ReCaptchaResponse();
	
	        if (trim ($answers [0]) == 'true') {
	                $recaptcha_response->is_valid = true;
	        }
	        else {
	                $recaptcha_response->is_valid = false;
	                $recaptcha_response->error = $answers [1];
	        }
	        return $recaptcha_response;
	
	}
}

if( !function_exists('recaptcha_get_signup_url') )
{
	/**
	 * gets a URL where the user can sign up for reCAPTCHA. If your application
	 * has a configuration page where you enter a key, you should provide a link
	 * using this function.
	 * @param string $domain The domain where the page is hosted
	 * @param string $appname The name of your application
	 */
	function recaptcha_get_signup_url ($domain = null, $appname = null) {
		return "http://recaptcha.net/api/getkey?" .  _recaptcha_qsencode (array ('domain' => $domain, 'app' => $appname));
	}
}

if( !function_exists('_recaptcha_aes_pad') )
{
	function _recaptcha_aes_pad($val) {
		$block_size = 16;
		$numpad = $block_size - (strlen ($val) % $block_size);
		return str_pad($val, strlen ($val) + $numpad, chr($numpad));
	}
}

/* Mailhide related code */
if(!function_exists('_recaptcha_aes_encrypt') )
{
	function _recaptcha_aes_encrypt($val,$ky) {
		if (! function_exists ("mcrypt_encrypt")) {
			die ("To use reCAPTCHA Mailhide, you need to have the mcrypt php module installed.");
		}
		$mode=MCRYPT_MODE_CBC;   
		$enc=MCRYPT_RIJNDAEL_128;
		$val=_recaptcha_aes_pad($val);
		return mcrypt_encrypt($enc, $ky, $val, $mode, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0");
	}
}

if(!function_exists('_recaptcha_mailhide_urlbase64') )
{
	function _recaptcha_mailhide_urlbase64 ($x) {
		return strtr(base64_encode ($x), '+/', '-_');
	}
}

if(!function_exists('recaptcha_mailhide_url') )
{
	/* gets the reCAPTCHA Mailhide url for a given email, public key and private key */
	function recaptcha_mailhide_url($pubkey, $privkey, $email) {
		if ($pubkey == '' || $pubkey == null || $privkey == "" || $privkey == null) {
			die ("To use reCAPTCHA Mailhide, you have to sign up for a public and private key, " .
			     "you can do so at <a href='http://mailhide.recaptcha.net/apikey'>http://mailhide.recaptcha.net/apikey</a>");
		}
		
	
		$ky = pack('H*', $privkey);
		$cryptmail = _recaptcha_aes_encrypt ($email, $ky);
		
		return "http://mailhide.recaptcha.net/d?k=" . $pubkey . "&c=" . _recaptcha_mailhide_urlbase64 ($cryptmail);
	}
}

if(!function_exists('_recaptcha_mailhide_email_parts') )
{
	/**
	 * gets the parts of the email to expose to the user.
	 * eg, given johndoe@example,com return ["john", "example.com"].
	 * the email is then displayed as john...@example.com
	 */
	function _recaptcha_mailhide_email_parts ($email) {
		$arr = preg_split("/@/", $email );
	
		if (strlen ($arr[0]) <= 4) {
			$arr[0] = substr ($arr[0], 0, 1);
		} else if (strlen ($arr[0]) <= 6) {
			$arr[0] = substr ($arr[0], 0, 3);
		} else {
			$arr[0] = substr ($arr[0], 0, 4);
		}
		return $arr;
	}
}

if(!function_exists('recaptcha_mailhide_html') )
{
	/**
	 * Gets html to display an email address given a public an private key.
	 * to get a key, go to:
	 *
	 * http://mailhide.recaptcha.net/apikey
	 */
	function recaptcha_mailhide_html($pubkey, $privkey, $email) {
		$emailparts = _recaptcha_mailhide_email_parts ($email);
		$url = recaptcha_mailhide_url ($pubkey, $privkey, $email);
		
		return htmlentities($emailparts[0]) . "<a href='" . htmlentities ($url) .
			"' onclick=\"window.open('" . htmlentities ($url) . "', '', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width=500,height=300'); return false;\" title=\"Reveal this e-mail address\">...</a>@" . htmlentities ($emailparts [1]);
	
	}
}
